• Journal of Preventive Medicine and Public Health
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• v.53 no.3
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• pp.198-204
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• 2020

Objectives: This study aimed to analyze the mortality of heart disease (HD), ischemic heart disease (IHD), and cerebrovascular disease (CeVD) through an age-period-cohort (APC) analysis. Methods: We used data on mortality due to cardiovascular disease from 1995 to 2018 in Japan, as determined by Vital Statistics. Age groups from 0 years to 99 years were defined by 5-year increments, and cohorts were defined for each age group of each year with a 1-year shift. We used Bayesian APC analysis to decompose the changes in the diseases' mortality rates into age, period, and cohort effects. Results: The period effects for all diseases decreased during the analyzed periods for both men and women. The cohort effects for men increased substantially in cohorts born from around 1940 to the 1970s for all types of cardiovascular diseases. The cohort effects of HD decreased in the cohorts born in the 1970s or later for both men and women. Regarding IHD and CeVD, either a non-increase or decrease of cohort effects was confirmed for cohorts born in the 1970s or later for men, but the effects for women showed a continuously increasing trend in the cohorts born in the 1960s or later. Conclusions: The cohort effects for IHD and CeVD showed increasing trends in younger generations of women. This suggests that preventive approaches against cardiovascular diseases are needed, particularly for women.

• Journal of Society of Preventive Korean Medicine
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• v.28 no.1
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• pp.69-87
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• 2024

Objectives : This study is to investigate the current National Health Insurance Database cohort studies related to complications of Parkinson's Disease (PD) and suggest the design of Korean medical epidemiological studies of PD. Methods : Nationwide longitudinal studies of PD patients in South Korea were collected through Pubmed and the Korea Citation Index (KCI). We selected cohort studies that used the National Health Insurance Database in Korea and targeted Parkinson's disease patients. Studies published before February 2024 were categorized according to study designs. We examined variables and covariates, enroll dates and matching methods. Results : Of a total of 536 studies, 18 studies met the inclusion criteria. All studies used the National Health Insurance (NHI) Research Database and among them, 5 used sample data and one senior database. Studies can be classified into two types. 11 cohort studies were comparing PD patients and non-PD patients. Another type was 4 PD patients cohort studies. Most studies used two diagnostic codes (G20 and V124) for inclusion criteria. Enroll periods were from 2002 to 2017, and follow-up periods were from 7 to 14 years. 16 studies considered age and sex as covariates. 15 studies used the propensity score matching method to increase the level of causality. There was only one study related to the Korean medical treatment. Conclusion : In future cohort studies on Korean medical treatment, more attempts should be made to reveal the effect of the treatments on PD patients by defining inclusion criteria for patient groups, covariates, exposure variables, and assessment indicators more operatively.

• The Korean Journal of Food And Nutrition
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• v.33 no.1
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• pp.98-104
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• 2020

The purpose of this study was to analyze a cohort, age, and time effects on sodium and sodium-calorie intake using the 2007~2017 Korea National Health and Nutrition Examination Survey (KNHANES). For analysis, we have constructed cohort panel data that combine KNHANES data in a time series. The age effect gradually increased from age 45~49 and then decreased afterwards. The time effect showed an increase in average sodium intake until 2010 followed by a subsequent decrease. The cohort effect showed that the sodium intake was the highest for the War of Liberation 1946~1953, and that the younger the latter, the lower the sodium intake. According to a cohort analysis, the younger the generation, the lower the sodium intake compared to the calorie intake, according to the baby boomers. Based on the results of this study, efforts should be made to educate and promote the dieting and providing low-salt meals to reduce sodium intake by generation. An analysis of the health hazards including sodium by generation and age is thought to enable the establishment relevant policies.

• Korean Medical Education Review
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• v.25 no.2
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• pp.102-108
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• 2023

This study shares details on the operating process and results of the cohort of students and graduates that was designed and implemented at Konyang University College of Medicine in Daejeon and discusses future directions for cohort establishment and improvement. First, Konyang University College of Medicine established the necessity and defined the purpose of cohort design and implementation. A task force was formed to establish guidelines for analysis targets, procedures, reports, and data management, and cohort operation was classified as a quality control activity. Data were collected through surveys of current students and graduates, and data generated during the curriculum were collected, analyzed, and reported every 2 years. The cohort data collection and analysis methods are designed by the Department of Medical Education, and data collection is carried out by the administrative team and each committee. Data management and analysis are handled by the Center for Medical Education Support, and analysis and reporting are conducted by the Department of Medical Education. Various members of the medical school are working to collect and analyze data, report findings, provide feedback, and improve. In the future, we plan to advance database computerization and work toward more effective data analysis. Cohort operation should not be another burden for medical schools; instead, it is hoped that operating cohorts will be a meaningful activity to increase the effectiveness of medical education and help in the operation and policy decisions of medical schools.

• Journal of Preventive Medicine and Public Health
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• v.53 no.6
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• pp.409-418
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• 2020

Objectives: This study conducted an age-period-cohort (APC) analysis of trends in healthy lifestyle behaviors in Japan. Methods: We used National Health and Nutrition Survey data on salt intake and prevalence of smoking, drinking, and physical activity between 1995 and 2018 in Japan. Age groups were defined from 20 years to 69 years old in 10-year increments. Cohorts were defined for each age group of each year with a 1-year shift, and cohorts born in 1926-1935 (first cohort) until 1989-1998 (last cohort) were examined. We conducted a Bayesian APC analysis, calculating estimated values for each behavior by age group, period, and cohort. Results: Estimated salt intake decreased from cohorts born in the 1930s to the 1960s, but increased thereafter in both genders, and the magnitude of increase was larger for men. Estimated smoking prevalence increased in the cohorts starting from the 1930s for men and the 1940s for women, and then decreased starting in the cohorts born in the 1970s for both genders. Although estimated drinking prevalence decreased starting in the cohorts born in approximately 1960 for men, for women it increased until the cohorts born in approximately 1970. Estimated physical activity prevalence decreased starting in the cohorts born in the 1940s in both genders, but the magnitude of decrease was larger for women. Conclusions: Trends in cohort effects differed by gender, which might be related to changes in the social environment for women. Improvements in dietary and exercise habits are required in more recently born cohorts of both genders.

• Women's Health Nursing
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• v.27 no.1
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• pp.27-39
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• 2021

Purpose: This study aimed to review recent findings from birth cohort studies on maternal and child environmental health. Methods: Birth cohort studies regarding environmental health outcomes for mothers and their children were investigated through a systematic review. A literature search was conducted in PubMed, CINAHL, the Cochrane Library, Embase, and RISS to identify published studies using the keywords using a combination of the following keywords: maternal exposure, environmental exposure, health, cohort, and birth cohort. Articles were searched and a quality appraisal using the Newcastle-Ottawa Scale for cohort studies was done. Results: A review of the 14 selected studies revealed that prenatal and early life exposure to environmental pollutants had negative impacts on physical, cognitive, and behavioral development among mothers and children up to 12 years later. Environmental pollutants included endocrine disruptors, air pollution (e.g., particulate matter), and heavy metals. Conclusion: This systematic review demonstrated that exposure to environmental pollutants negatively influences maternal and children's environmental health outcomes from pregnancy to the early years of life. Therefore, maternal health care professionals should take steps to reduce mothers' and children's exposure to environmental pollutants.

• Annals of Geriatric Medicine and Research
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• v.20 no.3
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• pp.114-117
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• 2016

A research project, the "Construction of Frailty Cohort for Elderly and Intervention Study," funded by the Ministry of Health and Welfare, has been ongoing since December 2015. The Korean Frailty and Aging Cohort Study (KFACS) aims to identify risk factors for adverse outcomes associated with frailty in community-dwelling older adults, as well as means of prevention. KFACS is a multicenter, longitudinal study, with the baseline survey being conducted in 2016-2017. The sample (n=3,000) consists of those aged 70-84 years, stratified by age and gender, recruited from urban and rural regions nationwide. An in-person interview and health examination are performed every 2 years. This project is also conducting many intervention studies. Project interventions focus on nutrition and exercise. The nutritional intervention study compares the effects of 1.2 g/kg versus 1.5 g/kg daily protein intake on sarcopenia and frailty in older Koreans. The exercise trial examines the effectiveness of an information and communication technology-based program in preventing or reducing frailty.

• The Journal of the Korea Contents Association
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• v.17 no.9
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• pp.396-405
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• 2017

Main purpose of this study is to analyze determinants of household debt among middle and old individuals aged between 32 and 76 that include Korean baby-boomers(born between 1955 and 1963), using a HAPC (Hierarchical Age-Period-Cohort) model and Korean Welfare Panel Study 2006-2016. This study includes 86,056 individuals. Research findings indicate that aging and period effects have statistically significant relationships with household debt levels, however, cohort effects including a baby-boomer generation do not. While household debt increases by 3,530,000 Korean won as age increases by one year, the rate of increase in household debt reduces as individual ages. In addition, employment and health status at the individual level have significant effects on household debt levels. The unemployed are more likely than the employed to have high household debt levels while unhealthy people tend than healthy people to have high household debt levels.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.26.1-26.15
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• 2023

Background: The objective of this study is to investigate the differences in incidence rates of targeted diseases by classification of occupations among construction workers in Korea. Methods: In a subject-based cohort of the Korean Construction Worker's Cohort, we surveyed a total of 1,027 construction workers. As occupational exposure, the classification of occupations was developed using two axes: construction business and job type. To analyze disease incidence, we linked survey data with National Health Insurance Service data. Eleven target disease categories with high prevalence or estimated work-relatedness among construction workers were evaluated in our study. The average incidence rates were calculated as cases per 1,000 person-years (PY). Results: Injury, poisoning, and certain other consequences of external causes had the highest incidence rate of 344.08 per 1,000 PY, followed by disease of the musculoskeletal system and connective tissue for 208.64 and diseases of the skin and subcutaneous tissue for 197.87 in our cohort. We especially found that chronic obstructive pulmonary disease was more common in construction painters, civil engineering welders, and civil engineering frame mold carpenters, asthma in construction painters, landscape, and construction water proofers, interstitial lung diseases in construction water proofers. Conclusions: This is the first study to systematically classify complex construction occupations in order to analyze occupational diseases in Korean construction workers. There were differences in disease incidences among construction workers based on the classification of occupations. It is necessary to develop customized occupational safety and health policies for high-risk occupations for each disease in the construction industry.

• Speech Sciences
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• v.9 no.2
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• pp.135-146
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• 2002

Generally a speaker verification system improves its system recognition ratio by regularizing log likelihood ratio, using a speaker model and its background speaker model that are required to be verified. The speaker-based cohort method is one of the methods that are widely used for selecting background speaker model. Recently, Gaussian-based cohort model has been suggested as a virtually synthesized cohort model, and unlike a speaker-based model, this is the method that chooses only the probability distributions close to basic speaker's probability distribution among the several neighboring speakers' probability distributions and thereby synthesizes a new virtual speaker model. It shows more excellent results than the existing speaker-based method. This study compared the existing speaker-based background speaker models and virtual speaker models and then constructed new virtual background speaker model groups which combined them in a certain ratio. For this, this study constructed a speaker verification system that uses GMM (Gaussin Mixture Model), and found that the suggested method of selecting virtual background speaker model shows more improved performance.